Alastair McClymont and I arrived in Lithuania on July 19. We are here once again to continue to support Lithuanian, Israeli, and American archaeologists and their students who are investigating Holocaust related sites in Vilnius and Kaunas. On Thursday July 20 and Friday July 21 we carried on from our June 2016 work at the Great Synagogue site, using electrical resistivity tomography and drone photography to try to discover the remaining subsurface architecture of the Synagogue and the bath house.The Great Synagogue was the largest and most important of the 140 synagogues and prayer houses that stood in Vilnius before 1941. Only a single synagogue, the Choral Synagogue, survived the War. The Great Synagogue was ransacked in 1941 by the Nazis, and levelled to the ground by the Soviets in 1957. In 1964, the Soviets built an elementary school over the site.As described in the NOVA documentary Holocaust Escape Tunnel, last year we somewhat speculated that we were in the mikveh, or Jewish ritual bath house. However the archaeologists are now 100% confident – they have excavated two actual mikvehs (Hebrew plural mikvaot), likely one for men and one for women. Which is which? There is no way to tell, as they are identical, and as bathing suits are not worn in the mikveh, there will be no telltale bathing garments left behind.